1. Field of the Invention
The present invention relates generally to a touch display device, and more particularly to a touch display device, which increases the ratio of good products and lowers the manufacturing risk.
2. Description of the Related Art
Along with the popularization of various mobile devices, human/device interface devices are widely applied to the mobile devices such as personal digital assistants (PDA), mobile phones and laptops. The human/device interface devices make the operation of the mobile devices more humanized. Especially, touch screen plays an important role in humanization of the operation of the mobile devices.
Currently, the integration methods of touch panel and liquid crystal panel can be mainly classified into on-cell touch technique and in-cell touch technique. With respect to the on-cell touch technique, the X-axis sensors and the Y-axis sensors of the projection capacitive touch panel are together made on a back face of the color filter (CF) of the touch panel as an integrated structure of the color filter.
With respect to the in-cell touch technique, the X-axis sensors and the Y-axis sensors are positioned in the LCD cell structure. In other words, in the in-cell touch technique, the touch sensors are integrated with the display panel, whereby the display panel itself has touch function. In this case, it is unnecessary to additionally attach or assemble the display panel with a touch panel. This technique is generally developed by TFT LCD panel manufacturers.
However, in both the in-cell touch technique and the on-cell touch technique, multiple sensors (X-axis sensors and Y-axis sensors) are disposed on the upper glass substrate or lower glass substrate of the LCD display panel. This increases the cost. Moreover, in the manufacturing process, the X-axis sensors and the Y-axis sensors must be bridged. This necessitates multiple masks so that the manufacturing process is complicated. As a result, the ratio of good products is lowered and the manufacturing cost is increased. Therefore, there is still room to improve the conventional touch display device.
According to the above, the conventional touch display device has the following shortcomings:    1. The manufacturing risk is high.    2. The ratio of good products is lowered.    3. The manufacturing cost is increased.